From: "Randy Brukardt" <randy@rrsoftware.com>
Subject: Re: Type safety on wikipedia
Date: Mon, 30 Jan 2006 20:13:52 -0600
Date: 2006-01-30T20:13:52-06:00 [thread overview]
Message-ID: <-YadnXqKU6ogW0PenZ2dnUVZ_tidnZ2d@megapath.net> (raw)
In-Reply-To: dreihb$712$1@pitr.home.jan
"Jan Andres" <jandres@gmx.net> wrote in message
news:dreihb$712$1@pitr.home.jan...
...
> Hmm, but aren't all the restrictions on the scope of access values
> actually there in order to guarantee type safety, as long as no unsafe
> constructs like 'Unchecked_Access are used? Or is
> Unchecked_Deallocation itself considered to be such an unsafe construct?
> If so, is there any "safe" alternative in Ada that we can use if we
> don't have GC?
>
> Of course you could simply avoid such constructs as quoted above but
> the downside is that the language will not actually enforce this.
The language (well, a compiler) can be made to enforce "No
Unchecked_Deallocation" using pragma Restrictions
(No_Unchecked_Deallocation); Similarly, you can prevent the use of
'Unchecked_Access with pragma Restrictions (No_Unchecked_Access); [Note that
these are program-wide, which might restrict the standard packages that you
can use.]
You can avoid using Unchecked_Deallocation if you can arrange for the access
type itself to go away, and then use a storage_pool for the storage. Or,
sometimes, you never need to free the data structure anyway (a compiler
symbol table comes to mind; it exists until the compile finishes). But both
of those are often impractical.
Randy.
next prev parent reply other threads:[~2006-01-31 2:13 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-26 7:28 Type safety on wikipedia Martin Krischik
2006-01-26 11:58 ` Alex R. Mosteo
2006-01-26 17:10 ` Martin Krischik
2006-01-26 20:24 ` Simon Wright
2006-01-26 20:43 ` Simon Wright
2006-01-27 6:58 ` Martin Krischik
2006-01-26 23:43 ` Bobby D. Bryant
2006-01-27 11:14 ` Alex R. Mosteo
2006-01-27 11:57 ` Martin Krischik
2006-01-27 15:30 ` Larry Kilgallen
2006-01-27 19:04 ` Martin Krischik
2006-01-27 22:06 ` Larry Kilgallen
2006-01-28 7:04 ` Martin Krischik
2006-01-29 21:48 ` Florian Weimer
2006-01-27 12:43 ` Georg Bauhaus
2006-01-26 13:49 ` Rod Chapman
2006-01-26 17:05 ` Martin Krischik
2006-01-26 18:14 ` Martin Krischik
2006-01-26 13:53 ` jimmaureenrogers
2006-01-26 15:18 ` Alex R. Mosteo
2006-01-26 16:49 ` Martin Krischik
2006-01-26 18:19 ` Alex R. Mosteo
2006-01-26 20:38 ` Simon Wright
2006-01-27 11:13 ` Alex R. Mosteo
2006-01-27 19:38 ` Simon Wright
2006-01-27 23:24 ` Randy Brukardt
2006-01-28 6:53 ` Martin Krischik
2006-01-27 18:58 ` Martin Krischik
2006-01-27 19:50 ` Simon Wright
2006-01-28 6:52 ` Martin Krischik
2006-01-26 19:22 ` Dmitry A. Kazakov
2006-01-26 19:07 ` Florian Weimer
2006-01-27 0:38 ` jimmaureenrogers
2006-01-27 18:54 ` Martin Krischik
2006-01-28 1:48 ` Jan Andres
2006-01-28 6:44 ` Martin Krischik
2006-01-31 2:13 ` Randy Brukardt [this message]
2006-02-06 5:02 ` Dave Thompson
2006-02-06 8:29 ` Larry Kilgallen
2006-01-27 11:34 ` Alex R. Mosteo
2006-01-27 12:18 ` Martin Krischik
2006-01-27 15:27 ` Florian Weimer
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